1. Field of the Invention
This invention pertains to the field of electronic digital computer systems and, in particular, to electronic digital computer systems having warning facilities.
2. Description of the Prior Art
In the early days of electronic digital computers, those computers contained operational registers that were represented by lights for each stage on a control panel. When the central processor was operating, the lights would flash as the registers were activated.
At the present time, it is not common practice to have register stages indicated by individual lights. Therefore, to enable the operator to be warned that the central processor is not operating, special provisions have to be made.
One prior art system manufactured and sold by the assignee of this invention involved a series of light emitting diodes (LED's) that were addressed to provide a pattern of light display when the central processor was active and to present no display when the central processor was not operating.
The present system uses a single LED and no pattern of light display as in the prior art. The present invention, in this preferred embodiment, provides a steady stage output from the LED when the central processor is active and a blinking output from the LED when the central processor is not operational.